throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testMappedToNull() {
    initMapWithNullValue();
    assertEquals(
        "Map.merge(keyMappedToNull, value, function) should return value",
        v3(),

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testElementSetReflectsAddAbsent() {
    Set<E> elementSet = getMultiset().elementSet();
    assertFalse(elementSet.contains(e3()));
    getMultiset().add(e3(), 4);
    assertTrue(elementSet.contains(e3()));
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testElementSetReflectsRemove() {

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(SEVERAL)
  public void testMultimapRemoveDeletesFirstOccurrence() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v0()));

    List<V> list = multimap().get(k0());
    multimap().remove(k0(), v0());
    assertContentsInOrder(list, v1(), v0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

      }
    }
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapFirst() {
    assertThrows(NoSuchElementException.class, () -> navigableMap.firstKey());
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapLast() {
    assertThrows(NoSuchElementException.class, () -> assertNull(navigableMap.lastKey()));
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapFirst() {

  return null
}

internal fun Headers.Builder.commonBuild(): Headers = Headers(namesAndValues.toTypedArray())

internal fun headersCheckName(name: String) {
  require(name.isNotEmpty()) { "name is empty" }
  for (i in name.indices) {
    val c = name[i]
    require(c in '\u0021'..'\u007e') {
      "Unexpected char 0x${c.charCode()} at $i in header name: $name"
    }
  }
}

internal fun headersCheckValue(

  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedAndUnsupported() {
    expectNullMissingWhenNullUnsupported("contains(null) should return false or throw");
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testContains_nonNullWhenNullContained() {

  }

  @MapFeature.Require(absent = ALLOWS_NULL_VALUE_QUERIES)
  public void testContains_nullNotContainedAndUnsupported() {
    expectNullValueMissingWhenNullValuesUnsupported(
        "containsValue(null) should return false or throw");
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testContains_nonNullWhenNullContained() {

      expectedEntries.add(Helpers.mapEntry(entry.getKey(), values().asList().get(index + 1)));
    }
    expectContents(expectedEntries);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionFeature.Require(KNOWN_ORDER)
  public void testReplaceAllPreservesOrder() {
    getMap()
        .replaceAll(
            (K k, V v) -> {
              int index = keys().asList().indexOf(k);

      if (containedClass.getSimpleName().equals("Require")) {
        if (containedClass.isAnnotation()) {
          assertGoodTesterAnnotation(asAnnotation(containedClass));
        } else {
          fail(
              rootLocaleFormat(
                  "Feature enum %s contains a class named "
                      + "'Require' but it is not an annotation.",
                  featureEnumClass));
        }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    collection.clear();
    assertTrue("After clear(), a collection should be empty.", collection.isEmpty());
    assertEquals(0, collection.size());
    assertFalse(collection.iterator().hasNext());
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testClear_unsupported() {